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Foxes - Options for Control
Andrew Horner and Stephen Platt
History of Introduction
The European Red Fox Vulpes vulpes was introduced into
Australia during the 1860's and 1870's although it was not
until the 1880's that the first viable population was
released. One reason for this action was to recreate "the
hunt" of old England for 'sporting' purposes.
The spread from these first releases around Melbourne was
rapid. By 1917 sightings had been recorded in Kalgoorlie
in Western Australia. The fox now ranges over two-thirds
of the Australian continent in habitats as diverse as semidesert through to rainforest and is known to be well
established in the urban areas of capital cities.
Biology
The fox is an opportunistic feeder and, although being
predominantly carnivorous, will vary its diet to include
fruit, insects and carrion as the season and food supply
permit. The diet in pastoral and agricultural areas is
known to consist in large proportion of rabbits and mice.
In bushland, native fauna such as possums, Brown
Antechinus and Bush Rats are commonly consumed.
Foxes construct extensive burrows where cubs are born
and reared. Rabbit warrens and Common Wombat
burrows, hollow logs and other sites may also be used.
Foxes breed once a year usually in late winter when three
to five cubs are born.
The home range of foxes varies with habitat type, food
availability and season. Foxes may range up to five sq km
or more with densities of 1-12 per sq km.
Impacts of foxes on fauna and farm
production
Since their introduction, foxes are thought to have had a
substantial impact across the Australian continent through
predation upon both native wildlife and introduced
domestic animals. Apart from the Dingo and domestic
dog, foxes are the largest terrestrial mammalian predator
on the Australian mainland. The Victorian fauna did not
co-evolve with the fox. Therefore, susceptible species
have not acquired adequate adaptations to avoid predation.
Foxes are highly mobile, being capable of climbing the
lower branches of trees and breaching tall fences.
June, 1993
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ISSN 1440-2106
Over 50 native species of animal have been recorded in the
diet of the fox.
Many threatened species are preyed upon by foxes and
foxes are thought to be a major factor in the decline of
some of these. Threatened species in the diet of foxes
include: Eastern Barred Bandicoot, Long-footed Potoroo,
Broad-toothed Rat, Mountain Pygmy-possum, Brush-tailed
Rock Wallaby, Broad-shelled Tortoise, Malleefowl,
Brolga, Hooded Plover and Little Tern.
For example, the Eastern Barred Bandicoot, which was
previously widespread in Victoria and remains common in
pastoral areas of Tasmania, is now threatened on the
mainland where it is restricted to a few individuals near
Hamilton in western Victoria. The fact that the fox has not
been introduced into Tasmania is a significant factor in
explaining the low numbers now recorded in Victoria.
The fox has been implicated in the extinction of six
mammal species in the Victorian Mallee.
A wide range of common species are also killed including
the platypus (see LFW Note 27).
Some native fauna have low population densities and even
low levels of fox predation on them may be significant to
their continued survival.
Foxes can reduce recruitment of susceptible species. For
example, foxes excavate and eat buried tortoise eggs and
prey upon Brolga chicks. Further, foxes may compete with
some native species (e.g. predatory birds, Tiger Quoll) for
food resources.
Foxes may play a role in maintaining reservoirs of diseases
harmful to wildlife and domestic animals such as
distemper, parvovirus, canine hepatitus and heartworm.
Foxes are also carriers of hydatid worms.
Foxes with sarcoptic mange (scabies) are thought to be
able to spread this disease into Common Wombat
populations.
Foxes assist in the dispersal of some environmental weeds,
such as Blackberries.
The fox in Europe is the main vector and reservoir host of
rabies and is therefore seen as the main threat for potential
spread of this disease should it ever be introduced into
Australia. Rabies can seriously affect humans. This threat,
of uncontrolled spread of rabies, was one of the main
reasons for the fox being declared as vermin under the
© State of Victoria, Department of Natural Resources and Environment 2002
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Foxes - Options for Control
Vermin and Noxious Weeds Act 1958 thus requiring
control by landholders.
The impact of the fox on the pastoral industry has not been
thoroughly investigated. Research has suggested that the
fox has been over-rated as a predator of otherwise viable
lambs; however, in some instances large numbers of lamb
deaths have been attributed to fox predation. Foxes also
disturb and kill poultry.
However, there is hope of limiting the effects of foxes.
Existing methods of fox control have proved successful in
the recovery of some threatened mammal species. For
example, a fox control program has led to increased
numbers of Numbats in Western Australia.
The main methods of control.
Fox control programs are most effective when they cover a
large area so that fox populations will take longer to
rebuild. This will usually involve a co-ordinated program
with adjoining landholders operating at the same time and
preferably more than once a year, ideally during Spring
and Autumn. Co-operative approaches will also reduce the
costs to individuals of fox control.
The planning and monitoring of fox control should be
thorough. Expert advice can be valuable at this stage. The
Department of Natural Resources and Environment offers
such advice. Advice is also available from private
consultants.
If fox control over the entire landscape is not feasible, then
provision of some 'safe havens', subject to intensive
control, for wildlife or domestic animals, may be an
alternative.
Fox control may lead to an increase in rabbit numbers or
feral cats. Therefore, control measures for a range of
introduced species may need to operate in unison.
Potential off-target poisoning of domestic dogs and
wildlife must be considered and limits the range of
techniques available for different situations. Larger
properties generally have more options available to them
than smaller properties located in areas with higher
densities of human populations.
The main techniques are:
1. Poisoning:
This method consists of laying a portion of meat, usually
liver or a prepared product known commercially as
FOXOFFR, in the soil at a depth of about 8 to 10 cm. The
poison used is commonly known as 1080 (ten eighty).
This is a restricted chemical and is not available to the
public. 1080 baits are only prepared and sold at some
nominated work centres of the Department of Natural
Resources and Environment (NRE). The NRE officer
authorised to issue or prepare the baits will assess the
suitability of the property or properties for a 1080 fox
baiting program. The NRE officer will need to be satisfied
that the laying of 1080 baits is warranted and can be done
in a safe manner. Landholders intending to lay baits must
inform neighbours of their intention to do so and display
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signs indicating that poison has been laid on their land.
This is a legal requirement and is done to safeguard against
the possibility of unintentional poisoning of domestic pets.
Baits that are not taken must be collected. The use of nonpoisoned baits (or 'free feed'), to assess the potential
impact on non-target species prior to a baiting campaign, is
advisable and may be mandatory.
2. Shooting:
One method involves a number of shooters spacing
themselves outside the bush or cover used by foxes and
sending in dogs to chase the foxes out into the open toward
the shooters. Small well-trained terrier-type dogs are
preferable as they are less likely to threaten wildlife such
as wallabies or kangaroos, which may use the same bush as
cover. A large fox hound or hunting dog is easily capable
of running down and killing a kangaroo. Spotlighting is
another method used with good results. A technique
known as "whistling" for attracting foxes, particularly
young cubs, toward the shooter by whistling is used
successfully by some hunters. Spotlight shooting is biased
toward taking yearling foxes and may not have the desired
impact on more experienced foxes.
Landholders may be able to obtain the services of
experienced shooters through local shooting organisations.
3. Fumigation:
Fumigants are also used for the control of foxes in their
den. Extreme care should be taken when handling any
fumigants (or other potentially dangerous chemicals).
Manufacturers' instructions and warnings should be
carefully observed. Fumigation programs will be most
successful in October when the cubs are still in the dens
during the day. Ask at your local NRE office for detailed
information on the use of fumigants.
4. Fencing:
The cost of erecting a high mesh fence capable of
excluding foxes is not a practical solution for most
situations. The electric fencing commonly found on farms
is not adequate to exclude foxes as the spacings are too
wide and the foxes have little difficulty in rapidly passing
between the wires of an operating fence. A well designed
and maintained electric fence with reduced distance
between wire spacings will, however, give a high degree of
control and should be a viable option to protect small
reserves or vulnerable livestock. NRE staff can provide
more detailed advice on appropriate designs.
5. Biological Control:
This method holds the hope of long term future control of
the fox population across the Australian continent.
Research is currently being undertaken by the CSIRO
Division of Wildlife and Ecology into immunosterilisation
as a viable method of fox control. Field application of
biological control techniques, should they be successfully
developed and socially acceptable, are unlikely to occur in
the next decade.
© State of Victoria Department of Natural Resources and Environment 2002
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Foxes - Options for Control
6. Fertility Control:
A range of fertility control chemicals are currently being
assessed. These may provide a control option in areas
where it is deemed unsafe or inappropriate to use poisoned
baits.
7. Other methods:
• Foxes will use large stands of noxious weeds, such as
blackberry and furze, for daytime shelter and to
establish den sites. Removal of this cover will reduce
the number of these sites.
• Environmental weed and pest animal (e.g. rabbit,
grasshopper) control may reduce the availability of
food for foxes and lead to lower population levels
although it may also encourage a shift in prey selection
toward native species or livestock.
• The use of treadle snares has proven to be effective in
some instances to capture foxes.
• Other methods of control, such as trapping with
oversize possum traps, have been trialed with little
success in Gippsland. The use of steel-jawed traps for
fox control is not target specific and is not
recommended. A landholder using these traps may be
in breach of the provisions of the Prevention of Cruelty
to Animals Act 1986.
• Foxes are able to move more easily along tracks.
Avoid placing tracks through native vegetation (see
also Note 23).
• It is possible to reduce the number and effects of the
fox population through the various control methods
described. Long term control requires landholders
within a district to adopt a group plan and co-ordinate
their efforts on an ongoing basis.
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Avoiding negative impacts on wildlife
Whilst foxes are a major concern for wildlife, fox control
measures may also adversely affect wildlife if not
conducted properly. For example, the Tiger Quoll is a
native carnivore that is likely to be susceptible to fox or cat
control methods using poisoned baits. It is therefore very
important that expert advice be sought and followed to
prevent impacts on native species. Buried bait, free
feeding and other techniques have been designed to
prevent non-target species being affected. Please take note
of the instructions given by NRE staff when conducting a
fox control program.
References and Further Reading:
Flora and Fauna Guarantee Action Statement No. 44. 'Predation
of Native Wildlife by the Introduced Red Fox'. Department of
Conservation and Natural Resources (CNR) and references listed
therein.
Land for Wildlife News Vol. 1, No's 2, 4, 5, 10.
Pest Animal Notes: 'The Fox', 'The Fox in Victoria', 'Fox
predation of livestock - the need for preventative control',
'Instructions for use of Foxoff baits for fox control', 'Use of 1080
poison baits for wild dog and fox control'. CNR.
This publication may be of assistance to you but the State of Victoria
and its officers do not guarantee that the publication is without flaw
of any kind or is wholly appropriate for your particular purposes
and therefore disclaims all liability for any error, loss or other
consequence which may arise from you relying on any information
in this publication.
Are there conflicts with protecting
wildlife habitat?
Areas managed for wildlife may contain dense areas of
vegetation or ground litter, including logs, that may
provide refuge for foxes.
The methods outlined in this Note can be used effectively
in bushland habitats without the need to make alterations to
the habitat itself.
Foxes persist in highly modified habitats. For example,
they survive on the docklands of Melbourne. Any attempt
at habitat modification to reduce fox numbers will need to
take into account the many benefits that native vegetation
can provide such as shade and shelter for livestock, erosion
control and wildlife habitat.
© State of Victoria Department of Natural Resources and Environment 2002
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